What is the @DataTableType annotation and how do you use it?

// Without custom type — messy manual mapping
@When("the admin creates these users:")
public void createUsers(DataTable dataTable) {
    List<Map<String, String>> rows = dataTable.asMaps(String.class, String.class);
    for (Map<String, String> row : rows) {
        String name  = row.get("name");
        String email = row.get("email");
        String role  = Role.valueOf(row.get("role"));   // manual conversion
        int    age   = Integer.parseInt(row.get("age")); // manual conversion
        createUser(name, email, role, age);
    }
}

// User POJO
public class UserData {
    public String name;
    public String email;
    public String role;
    public int    age;

    public UserData(String name, String email, String role, int age) {
        this.name  = name;
        this.email = email;
        this.role  = role;
        this.age   = age;
    }
}

// DataTableTypeRegistry.java — define the transformation
public class DataTableTypeRegistry {

    @DataTableType
    public UserData userEntry(Map<String, String> entry) {
        return new UserData(
            entry.get("name"),
            entry.get("email"),
            entry.get("role"),
            Integer.parseInt(entry.get("age"))
        );
    }

    @DataTableType
    public ProductData productEntry(Map<String, String> entry) {
        return new ProductData(
            entry.get("name"),
            new BigDecimal(entry.get("price").replace("$", "")),
            entry.get("category")
        );
    }
}

Scenario: Admin creates multiple users
  When the admin creates these users:
    | name      | email              | role    | age |
    | John Doe  | john@example.com   | ADMIN   | 30  |
    | Jane Smith| jane@example.com   | MANAGER | 28  |
    | Bob Lee   | bob@example.com    | USER    | 25  |
  Then all 3 users should appear in the user management list

@When("the admin creates these users:")
public void createUsers(List<UserData> users) {  // ← Cucumber auto-converts
    for (UserData user : users) {
        adminPage.createUser(user.name, user.email, user.role);
    }
}

@Then("all {int} users should appear in the user management list")
public void verifyUsers(int expectedCount) {
    assertEquals(expectedCount, adminPage.getUserCount());
}

// Feature file
When the user updates their profile to:
  | firstName | John    |
  | lastName  | Doe     |
  | phone     | 9876543 |

// Step definition receives a single object
@When("the user updates their profile to:")
public void updateProfile(UserData updatedData) {  // ← single object
    profilePage.updateName(updatedData.firstName + " " + updatedData.lastName);
    profilePage.updatePhone(updatedData.phone);
}

// For JSON/XML in feature files:
@DocStringType
public JsonNode json(String docString) throws Exception {
    return new ObjectMapper().readTree(docString);
}

// Feature file:
When I send request with body:
  """json
  {"name": "John", "role": "ADMIN"}
  """